It is well known that when a silver halide color photographic material is subjected to color development, an oxidized aromatic primary amine color developing agent reacts with a coupler to form a dye such as an indophenol, an indoaniline, an indamine, an azomethine, a phenoxazine, a phenazine and the like, thus forming a color image. In order to form a magenta color image, a 5-pyrazolone coupler, a cyanoacetophenone coupler, an indazolone coupler, a pyrazolobenzimidazole coupler or a pyrazolotriazole coupler is generally employed.
Magenta color image forming couplers which have been widely used in practice and on which various investigations have been made are almost all 5-pyrazolones. It is known that dyes formed from 5-pyrazolone couplers are excellent in fastness to heat and light but they have an undesirable absorption of yellow component in the region around 430 nm, which causes color turbidity.
In order to reduce yellow component absorption, a pyrazolobenzimidazole nucleus as described in British Pat. No. 1,047,612, an indazolone nuclues as described in U.S. Pat. No. 3,770,447 and a 1H-pyrazolo[5,1-c][1,2,4]triazole nucleus as described in U.S. Pat. No. 3,725,067 have been proposed as a magenta color image forming coupler skeleton. Further, a 1H-imidazo[1,2-b]pyrazole nucleus as described in Japanese patent application (OPI) No. 162548/84, a 1H-pyrazolo[1,5-b][1,2,4]triazole nucleus as described in Japanese patent application (OPI) No. 171956/84, a 1H-pyrazolo[1,5-d]tetrazole nucleus as described in Japanese patent application (OPI) No. 33552/85 and a 1H-pyrazolo[1,5-b]pyrazole nucleus as described in Japanese patent application (OPI) No. 43659/85 have been recently proposed as novel magenta color image forming coupler skeletons.
Among these magenta couplers, the magenta dyes formed from the 1H-pyrazolo[5,1-c][1,2,4]triazole couplers described in U.S. Pat. No. 3,725,067 and British Pat. Nos. 1,252,418 and 1,334,515; the 1H-imidazo[1,2-b]pyrazole couplers described in Japanese patent application (OPI) No. 162548/84, the 1H-pyrazolo-[1,5-b][1,2,4]triazole couplers described in Japanese patent application (OPI) No. 171956/84; the 1H-pyrazolo[1,5-d]tetrazole couplers described in Japanese patent application (OPI) No. 33552/85; and the 1H-pyrazolo[1,5-b]pyrazole couplers described in Japanese patent application (OPI) No. 43659/85 show excellent absorption characteristics free from the undesirable absorption of yellow component as described above in a solvent such as ethyl acetate, dibutyl phthalate, etc., and thus they provide preferable color separation.
Of these magenta couplers, however, the 1H-pyrazolo[5,1-c][1,2,4]triazole type couplers provide azomethine dyes which have remarkably low fastness to light and greatly reduce the desired properties of color photographic light-sensitive materials, in particular, color photographic light-sensitive materials for prints. Further, other novel nitrogen containing heterocyclic 5-membered ring-condensed-5-membered ring couplers as described above provide azomethine dyes having light fastness which is insufficient for use in color photographic light-sensitive materials, particularly in color photographic light-sensitive materials for prints.
In order to improve light fastness of dyes formed from these nitrogen containing heterocyclic 5-membered ring-condensed-5-membered ring couplers, there have been proposed a method wherein an organic color image stabilizing compound is incorporated into a photographic layer as described in Japanese patent application (OPI) No. 125732/84 and a method wherein a metal complex mainly composed of salicilaldoxy type is incorporated into a photographic layer as described in Japanese patent application (OPI) No. 97353/85. Photographic materials containing these compounds, in fact, exhibit improved light fastness. However, the improvement in light fastness is still insufficient and, thus, it has been desired to develop a color image stabilizer which has greater effects.
Further, most of metal complexes are colored themselves and therefore, when they are incorporated in a large amount, a problem occurs in that white background is colored.